The present invention relates to a recording method and a recording device, which are suitable for the application to e.g. a video camera recorder that uses e.g. a recordable DVD (Digital Video Disc or Digital Versatile Disc) as a recording medium and is operable to record a moving image, etc. on the DVD.
In recent years, there have been developed various kinds of video playback devices which use a disc recording medium with a large capacity such as DVD as a recording medium. Also, a disc playback device (so-called camera recorder) integrated with a video camera has been commercialized in various kinds of products.
In a video playback device using a disc like this as a recording medium, it is possible to record on the disc until all the predetermined storage capacity thereof is occupied. For example, in the case of using a disc having a capacity that allows video data of a moving picture to be recorded for an hour at a certain bit rate, successive recording on the disc can be made for an hour.
Meanwhile, in recording video data on a disc such as DVD, the data is accompanied with a recording unit referred to as a title and a sub-recording unit referred to as a chapter, provided that each title is divided into two or more chapters. The format of DVD video determines the upper limit number of titles recordable on a disc and the maximum number of chapters within a title. Specifically, the number of titles recordable on a disc is set to ninety-nine (99), and the maximum number of chapters within a title is set to 99.
As for the chapter, in the case where recording is performed in a video camera recorder, a chapter is set in one recording. Specifically, for example, in the case where a user carries out an operation to start recording and then performs an operation to stop the recording, if one continuous record of video data of a moving picture is performed at the time when the recording is stopped, the one record of the video data of the moving picture is accompanied with one chapter number. When start and stop of recording are repeated and then the 99th chapter is recorded, the title number is incremented by one in recording next time, additional data is recorded as the first chapter of the resultant title number.
In the case where recording is continued in this way, and then up to 99 chapters of the title number 99 are recorded on one disc, an additional recording after that is not enabled because the chapter having the maximum number of the title with the maximum number has been recorded even if the disc has an unoccupied capacity. The patent document, JP-2004-201170 contains the description on the number of titles and the number of chapters that are recordable according to the DVD video format.
In the meantime, causes of the change in title based on DVD video format include the change in recording condition of video data in addition to the above-described number of chapters that has reached the maximum and the title forced to be changed by a user operation. Specifically, pieces of video data recorded in a title must be of the same format. Therefore, when an operation to change the recording format or recording mode is performed in the middle of recording, the title number of a title to be recorded next time is changed to the number resulting from increment of the current title number by one at the time of performing such operation.
More specifically, two or more recording modes are prepared as modes for recording in e.g. DVD video, and the bit rate and image size of data are changed depending on the recording modes. Therefore, the maximum length of time during which recording can be performed on one disc is changed. For example, there is a type of recorder in which the following modes are prepared: HQ mode that enables twenty (20) minutes of recording on one disc; SP mode that enables thirty (30) minutes of recording; and LP mode that enables sixty minutes of recording. (The names such as HQ mode and SP mode and the length of time during which recording can be executed may differ among manufacturers of recorders.) Now, when a change in recording mode that causes particularly the change in image size (the number of pixels that constitute an image of one frame) is made, the title must be changed to another title.
Also, in the case where an operation that causes the change in aspect ratio of an image to be recorded is executed, the recorded title is changed to another one.
In the case where a change in mode or recording condition like this alters the title, if the title number of a title in the middle of the recording on the disc is sufficiently smaller than the maximum title number, there is no particular problem, but in the situation where titles of up to the maximum number have been recorded, an additional recording on the disc is disabled concurrently with execution of the change in mode or recording condition even when the disc has an unoccupied capacity.
In other words, in the case of simply repeating start and stop of image recording, recording can be executed to the 99th chapter of the 99th title. Therefore, for example, it is assumed that a user has confirmed through display that the disc still has a remaining capacity which allows recording to be executed for 10 minutes in the current mode after having recorded the 19th chapter of the 99th title. In this case, if the recording mode is left as it is, recording can be performed up to the 99th chapter having the maximum chapter number, and additional 80 chapters can be recorded as long as the disc has a remaining capacity.
However, when a user performs an operation to change the recording mode or the aspect ratio of a recorded image in this situation, the title must be changed concurrently with the operation, whereas the disc is changed to the state in which it has no recordable remaining capacity suddenly after the change because the titles of up to the maximum title number have been already recorded and therefore there is no room to change the title on the disc.
The reason why such situation takes place is difficult to understand for the user who has executed the operation in many cases. This is because the display is changed to no remaining capacity for recording suddenly after the execution of an operation to change the mode or the like, while the user has confirmed through guidance display that a capacity for recording remains sufficiently.
In the above description, the problems in the case where recording is performed in a video camera recorder according to the DVD video format have been described. However, there are similar restrictions in association with recording units in general also when data such as video data is recorded on a recording medium such as a disc based on another format. Therefore, in the case where recording is executed on such recording medium having restrictions in association with recording units, similar problems arise in recording.